This invention relates to an assist apparatus for a pedal such as a clutch pedal for a motorcar or the like.
Various apparatuses of this kind have been known such as the type shown in FIGS. 1 and 2. In such a Prior Art apparatus, a pedal arm b is supported through a supporting shaft e on a machine frame a so as to be turnable between its inoperative position on one side and its operative position on the other side. A first spring seat c and a second spring seat d facing the first spring seat c are turnably connected on a crank arm extension of the pedal arm b and the machine frame a, respectively. That is, the first spring seat c is supported by a first seat shaft f on the crank arm extension of the pedal arm b and the second spring seat d is supported by a second seat shaft g on the machine frame a. The seat shafts f, g, are parallel with the supporting shaft e. A spring means i comprising a compression coil spring mounted on a guide rod h is provided between the two seats c, d so that the two seats c, d may be urged thereby along a direction of a connecting line connecting between the axis of the first seat shaft f and the axis of the second seat shaft g. In this manner, when the pedal arm b is turned, the first seat shaft f is turned to move to one side or the other side across a line connecting between the axis of the supporting shaft e and the axis of the second shaft g. A torque represented by product of a resilient force of the spring means i and an offset length l.sub.1 of the line of action of the spring means i from the supporting shaft e is applied to the pedal arm b. (Japanese Utility Model Publication SHO No. 51-35863). In this type of apparatus, if the distance l.sub.2 between the seat shafts f, g is decreased, a swing angle of the line of action of the spring i can be increased to obtain a larger torque. Additionally, the second spring seat d can be supported on the second seat shaft g provided on the machine frame a which is located near the first seat f, through an L-shaped bracket j extending sideways and inwards from an outer end portion of the rod h attached to the seat d. This arrangement, however, has the disadvantage that because a supporting portion for bearing the second seat shaft g is applied with a bending moment corresponding to an axial or longitudinal distance l.sub.3 thereof from the second spring seat d, in addition to being applied with a radial load caused by the resilient force of the spring means i, a smooth turning of the seat d about the shaft g cannot be obtained. Additionally, because the first seat shaft f is positioned at an outer end of the first spring seat c, the distance from the shaft f to the outer end of the rod h becomes large.